1株异养脱氮菌降解壬基酚聚氧乙烯醚的研究

研究了异养脱氮菌Bacillus sp.LY降解壬基酚聚氧乙烯醚(NPEOs)的性能.结果表明,该菌株具有较强地降解NPEOs的能力,且在实现NPEOs降解去除的同时表现出一定的异养脱氮性能.降解14d后, Bacillus sp.LY对NPEOs去除率达95.6%,对体系中的总氮去除率为43.9%.该菌株对NPEOs的降解去除符合一级动力学特征,其降解速率常数为0.224d-1.该菌株通过无氧化过程的乙氧基链的逐渐缩短的途径降解去除NPEOs,可避免产生危害性更大的NPEOs的羧酸化产物(NPECs).在分别以氨态氮(NH4C1)、硝态氮(NaNO3)和亚硝态氮(NaNO2)3种不同氮素为氮源的条件下,菌株对NPEOs均具有一定的降解效果,其中以氨态氮为氮源时菌株对NPEOs降解效果最好.研究结果可为消除壬基酚聚氧乙烯醚与氮素复合污染提供理论依据.

Biodegradation of Nonylphenol Ethoxylates by a Bacterial Strain with Heterotrophic Nitrogen Removal Ability

Biodegradation of nonylphenol ethoxylates(NPEOs) by Bacillus sp.LY with heterotrophic nitrogen removal ability was investigated.The study showed that Bacillus sp.LY could biodegrade NPEOs largely combined with heterotrophic nitrogen removal.After 14d,removal efficiency of NPEOs was 95.6% and removal rates of TN was 43.9%.Biodegradation of NPEOs by the strain Bacillus sp.LY conformed to the first-order kinetic model,with biodegradation rate constant 0.224 d^-1. NPEOs were biodegraded through a nonoxidative pathway with sequential removal of ethoxyl units.Moreover,no more harmful nonylphenoxyacetic acids were formed by this pathway.NPEOs could be degraded by Bacillus sp.LY in the presence of different nitrogen contaminants NH₄Cl,NaNO₃ and NaNO₂. The removal efficiency of NPEOs was highest in the presence of ammonium.Results may make contribution to the efficient removal of compound contamination of NPEOs and nitrogen contaminants.